Oli Hawkins admitted Pompey found their Wycombe Wanderers encounter tough.
Yet Kenny Jackett’s men still departed Adams Park with a fifth-successive victory to maintain their automatic promotion interest.
Brett Pitman netted twice and top-scorer Jamal Lowe grabbed the other as the Blues secured a 3-2 triumph this afternoon.
However, once Scott Kashket grabbed a lifeline eight minutes from time with a stunning strike, a nervy finale was initiated.
Still, Pompey stood firm to put themselves within two points of Barnsley and Sunderland, who both now share second place in League One.
Hawkins said: ‘We always knew it was going to be tough coming here, the record of the top six clubs in the league showed no-one had won here previously.
‘A lot of their pressure was putting the ball into the box, Craig (MacGillivray) made some great saves and we held on and got the three points.
‘It seemed in the second half we were having goal-kicks every two minutes and they were having free-kicks every two minutes – we couldn't kill the game off or get a hold of the ball much.
‘Then Akinfenwa comes on and you know what they are going to do, but Burgey and Clarkie dealt with him brilliantly, all we had to do was stay solid.
‘We could have gone on and won three or four one, but won 3-2 and held on at the end and that’s football.
‘Wycombe built pressure, had an off-side goal and then Scott Kashket scored a really good one.
‘It was tough – but we held on.’